Transmission mechanism



Aug. 4, 1931.

G. E. HOWARD TRANSMISSION MECHANISM Filed April 10, 1929 w? SYFQIZLAJ m Patented Aug. 4, 1931 UNITED STATES GEORGE E. nowaanfor BIT/rum, PENNSYLVANIA i TRANSMISSION MECHANISM Application filed April 10,

My invention relates to fluid transmission mechanism of the type wherein the pressuregenerating unit includes a cylinder barrel containing "a plurality of cylinders and pistons, the said parts being rotatable as a unit and the pistons simultaneously reciprocated to place fluid, such as oil, under pressure, the pressure being utilized to impart power to an element which is to be driven.

One object of my invention is to provide in an apparatus of the type referred to, means whereby greater horsepower may be developed through the use of machines or apparatus much smaller than those heretofore deemed necessary.

Another object of my invention is to provide a device of the character described wherein there is less tendency toward leakage of the fluid between relatively moving parts of the system.

Still another object of my invention is to simplify and improve generally the structure and operation of devices of the character refcrrcd to.

One form which my invention may take is shown in the accompanying drawings, wherein Figure 1 is a longitudinal sectional view of a fluid-pressure generating-unit and a portion of the motor unit driven thereby, and Fig. 2 is a view taken on the line II-II of Fig. 1.

The general arrangement of parts is similar to various forms of apparatus well-known in the art, but the mechanism shown on the drawings distinguishes from such art more especially in the provision of means for counterbalancing thrusts which result from the compression of the motive fluid by the pistons referred to.

As shown on the drawings, I provide a fluid-pressure generating unit 3 which transmits power from a driving shaft 4 to a driven shaft 5 through a fluid pressure motor unit 6. The shaft 4 may be driven from any suitable source of motive power, such as an internal combustion engine, while the shaft 5 may have driving connection with an axle or other apparatus which it is desired to operate.

I have shown a swash plate 7 that is tiltably or pivotally mounted upon a shaft 4 and 1929. Serial No. 354,152.

which is rotated by the shaft. The swash plate may be of any well-known form, and may be tilted to any desired angle, depending upon the length of stroke which it is desired to impart to the pistons which are employed for placing motive fluid under pressure.

Connecting rods 8 have ball and socket connection with the swash plate 7 and with pistons 9 that are reciprocable in cylindrical bores 10 of a cylinder barrel 11. The cylinder barrel has rotative movement with respect to a manifold block 12 which has chambers 13 and 14 through which fluid under pressure may be discharged by the pistons 9 at one side of the apparatus and through which fluid to be compressed may be drawn into the cylinders 10 at the other side of the apparatus, depending upon whether the unit- 3 is functioning as a generator or as a motor. Fluid which may be discharged from certain of the cylinders 10 through the header chamber 14, for example, will be forced into cylindrical bores 15 of a cylinder barrel 16 that is contained within the unit 6 during such time as the cylindrical bores 10 are passing across the slot or chamber 14. The cylinder barrel 16 is rotatable with respect to the block 12 and contains pistons (not shown) which may be connected to a swash plate corresponding to the plate 7 and which may be connected to the shaft 5 after the manner of the connection of the plate 7 to the shaft 4. In other words, the details of the unit 6 may be substantially the same as those shown in connection with the unit 3 and therefore no detailed description of the unit -6 is necessary to an understanding of this invention.

The cylinder barrel 11 is keyed to the shaft 4 as at 18, and the shaft 4 is supported in bearings 19 and 20 that are carried by the manifold block 12 and the casing of the unit 3 respectively. The cylinder barrel 11, to-

gether with the swash plate 7, will be rotated in unison with the shaft 4, and during such rotation, the swash plate 7 will be oscillated about its pivot 21, to thereby effect reciprocation of the pistons 9. Assuming that the shaft 4 is rotating in a clockwise direction and that the pistons 9 at the right hand side of the apparatus as viewed in Figs. 1 and 2 are serving to compress oil or other fluid within the system, compressed fluid will be discharged through the arcuate chamber 14 to those cylindrical bores 15 that happen to be opposite thereto, thus imparting movement to pistons contained within the bores 15 and effecting transmission of power to the driven shaft 5.

The pressures thus developed tend to force the cylinder barrels 11 and 16 away from the manifold block 12 at the points 23 and 23a, for example, and thus permit escape of oil past the bearing surfaces at 23. In order to overcome this tendency, or in other .words to. counterbalance the thrusts thus developed at 23, I provide a by-pass 24 in the block 12 that communicates with a pipe 25 which leads to an expansible element 26 which may be made of copper or other flexible material and which will tend to expand under fluid pressure, after the manner of a sylphon.

The expansible element 26 is interposed between a stop collar 28 that has threaded engagement'with the interior wall of the unit casing and a bearing late 27 that supports the upper race of a ba l-hearing unit 29, the lower race of such unit being supportednpon an annular flange 30 of the cylinder barrel 11.

It will be seen that with the parts operating as above described, fluid pressure will be diverted through a port 24, to the expansible element 26, with a force bearing direct relation to the pressure within the bores 10 and the chamber 14. The fluid pressure element 26 is of sucharea that the expansible force developed therein will substantially counterbalance the reactive force resulting from the thrusts of the three pistons 9 which happen to be passing across the chamber 14, so that the tendency for the co-operating bearing surfaces of the cylinder barrel 11 and the block 12 .to separate will be counteracted.

In a similar manner, fluid pressure is diverted through a pipe 32 to a sylphon'within a bearing plate 33 which corresponds to the bearing plate 28, to counteract thrusts on the barrel 16, and to maintain the surfaces at 23a in proper working engagement. v

This arrangement avoids the necessity, of restricting the discharge ends of the bores 10, for example, to counteract the thrusts resulting from the passage. of fluid under. pressure from these bores, thus permitting freerflow of the fluid and preventing unnecessary heating of the motive fluid, as well as generally increasing the efliciency of the apparatus.

At the opposite side of the apparatus, I provide a pipe 34 which has connection with the chamber 13 and with a sylphon-like expansible element 35 that correspondsto the element 26. When the chamber 14 is functioning as a pressure'chamber, the chamber .13 will be serving as a suction or intake chamher for the piston bores 10 as they pass over the same and there will be no pressure in the element 35.

A spring 37 that is interposed between a collar 38 on the shaft 4 and the adjacent ends of the cylinder barrel 11 is of sulficient strength to hold the barrel 11 in close-fitting engagement with the block 12, when the parts are idling, that is, when the swash plate 7 is turned to a plane perpendicular to the shaft 4.

In case the unit 3 is functioning as the-motor 01' driven unit and the unit 6 as the generating unit, the chamber 13 will be the pressure chamber and the chamber 14 the suction chamber. In that event, the expansible element 35 will be expanded slightly. It will be understood that any longitudinal movement of the cylinder barrels under fluid pressure is almostimperceptible, but that even very slight movement would'be sufiicient to permit leakage of fluids past the bearing surfaces 23, and that the expansible elements 26 need havebut very slight range of movement.

The thrust plate or collar 28 is adjustable to take up such slight wear as may accur at the thrust surface 23 or in the bearings. Screws 40 extend through the collar 28 into the bearing plate 27 to hold such plate against rotative movement through drag imparted thereto by the rotation of the barrel 11, these screws being of course removed when it is desired to effect adjustments of the collar 28. The collar may be provided with a suitable number of circumferentially-spaced holes, so that the screws can always be inserted through the collar 28 in alinement with the two holes contained in the bearing plate 27.

I claim as my invention 1. The combination with arotatable cylinder barrel containing a cylindrical bore offset from the axis of the barrel and having a discharge opening at one end and a piston reciprocable therein, of a bearing surface for said end of the barrel, a thrust bearing surface on the barrel similarly offset from said axis, an expansible element engaging said thrust bearing surface for only a portion of the distance circumferentially of the said axis to hold the barrel against said bearing surface, and means for diverting fluid pressure from said bore to said expansible element.

2. The combination with a rotatable cylinder barrel containing a plurality of cylindrical bores spaced circumferentially of the barrel and having discharge openings at one end and pistons reciprocable in the bores, of a bearing surface for said end of the barrel a thrust bearing mounted on the barrel, expansible elements having engagement with said thrust bearing to maintain the barrel in engagement with said bearing surface, and

means for directing fluid from said bores successively to one of the said expansible elements, during rotation of the barrel in one direction and to another expansible element during rotation of' -thelbarrel the opposite 7 direction.' r 3. The combination with a rotatable cylinder barrel having a cylindrical bore offsetfrom the axis of the barrel and a discharge opening from said bore, of a piston reciprocable in the bore, a bearing surface -on the barrel having a port; in position to receive fluid discharged from said opening, a thrust bearing surface'positioned to hold the barrel in engagement with said surface and similarly oflset from'the axis of the barrel, an expansible element positioned against said thrust bearing surface and extending for only a portion of the distance circumferentially of the said axis, and means for diverting fluid from said cylindrical bore to said expansible element.

The combination with a rotatable cylinder barrel containing a plurality of cylindrical bores spaced circumferentially of the barrel and having discharge openings at one end and pistons reciprocable in the bores, of a bearing surface for said end of the barrel having circumferentially spaced ports in position to successively communicate with said openings during rotation of the barrel, a thrust bearing positioned to hold the barrel in engagement] with said bearing surface, circumferentially-spaced expansible elements engaging said thrust bearing, and means controlled by movement of the barrel for direct ing fluid pressure to said expansible elements. 5. The combination with a rotatable cylinder barrel containing a plurality of cylindrical bores spaced circumferentially of the barrel and having discharge openings at one end and pistons reciprocable in the bores, of a bearing surface for saidend of the barrel having circumferentially-spac ed ports in position to successively communicate with said openings during rotation of the barrel, a

thrust bearing positioned to hold the barrel in engagementwith said bearin fl surface, circumferentially-spaced expansible. elements engaging said thrust bearing, and a conduit connected to each of said ports and one of the expansible elements for diverting fluid pressure to said element.

6; The combination with a rotatable cylin- I der barrel containing a plurality of cylindrical bores spaced circumferentially of the barrel and having discharge openings at one end and pistons reciprocable in the bores, of

a bearing surface for said end of the barrel I having two ports in position to successively communicate with said openings during rotation of the barrel, a thrust bearing positioned to hold the barrel in engagement with said bearing surface, an expansible element spaced from each of said ports in a direction longitudinally of the barrel and having engagement with said thrust bearing, and means for directing fluid pressure into said expansible elements during rotative movements of the barrel.

7. The combination with a rotatable cylinder barrel containing a plurality of cylindrical bores spaced circumferentially of the barrel and having discharge openings at one end and pistons reciprocable in the bores, of a bearing surface for said end of the barrel having circumferentially-spaced ports in position to successively communicate with said openings during rotation of the barrel, a thrust bearing positioned to hold the barrel in engagement with said bearing surface, circumferentially-spaced expansible elements engaging said thrust bearing, and a conduit connected to each of said ports and one of the expansible elements for diverting fluid pressure to said element, the said expansible elements being of crescent form and each partially encircling the axis of the barrel.

In testimony whereof I, the said GEORGE E. HOWARD, have hereunto set my hand.

- GEORGE E. HOWARD. 

